We all know that our free personal dev instances have a limit of 10 days of inactivity, then it's returned to the pool and it's a pain to try and get a new one. Solution for many has been that once a week go in and do something, like create a client script. This just so your counter for inactivity should be reset. Well, now they have made a new function which help with this.
Log on to http://developer.servicenow.com and click on manage. Now you have a new button called "Extend instance". Pressing this will reset the inactivity timer to another 10 days.